Refrigeration apparatus for motor vehicles



H. O.-YKIRKPATRICK REFRIGER TION APPARATUS FOR MOTOR VEHICLES Aug. 26, 1952 Filed oci. 4, 1949 INVENTOR.

HEN/{Y 0- lf/fikfin TRICK A TTOKNfYS Patented Aug. 26, 1952 REFRIGERATION APPARATUS FOR MOTOR VEHICLES Henry 0. Kirkpatrick, Detroit, Mich., assignor to Coldmobile Company, Detroit, Mich., a corporation of Michigan Application October 4, 1949, Serial No. 119,426

7 Claims.

This invention relates to a refrigerating apparatus for a motor vehicle.

It is an object of this invention to produce a refrigerating apparatus for a motor vehicle which is adapted to receive its power from a generator which is driven by the vehicle engine or a battery connected therewith while the vehicle is running and from a standard 110 volt alternating current outlet when the vehicle is parked, such as overnight.

The invention generally contemplates a refrigerating apparatus having a compressor motor and an air circulating motor of the direct current low voltage type which are arranged to be connected for operation to a conventional storage battery on the vehicle or to a standard 110 volt alternating current outlet through a step down transformer and a rectifier.

More specifically, the invention contemplates an electrical arrangement on a motor vehicle which includes a generator operated by the vehicle engine, a refrigerating apparatus, and two storage batteries arranged to be maintained in a charged condition by the generator, one storage battery providing the necessary current for the lights, ignition system, etc., of the vehicle, while the other battery provides current for the refrigerating apparatus when the current being developed by the generator is insuflicient to meet the needs of the refrigerating apparatus, such as when the compressor motor is started.

The drawing shows a, diagrammatic view of a refrigerating apparatus for a motor vehicle embodying my invention.

As is shown in the drawings, the refrigerating apparatus comprises a conventional arrangement which includes a compressor ID for the refrigerant which isbelt driven from a motor I I. The compressor outlet is connected by a conduit l2 to a condenser (3 which is in turn connected to a receiver I4 by a conduit 15. From receiver I4 the refrigerant is conducted by a conduit I6 through an expansion valve I1 and thence to an evaporator l8 through conduit IS. The outlet of evaporator I8 is connected by a conduit 20 with the inlet of compressor II]. An air circulating fan 2| driven by a motor 22 directs air from the refrigerated compartment (not shown) against evaporator It so as to cool the air. Motors II and 22 are designed to be operated on direct current at low voltage, that is, at about twelve volts.

The current generating source on the vehicle comprises a conventional three phase alternator 25 which is arranged to be driven, by a belt 26 from the crank shaft of a vehicle engine 21. Alternator 25 is of the revolving field type, the stator in which the current is generated being connected to a rectifier 28 by three conductors 26, 36 and 3|. Rectifier 28 is preferably of the dry plate type and designed for three phase, full wave rectification. The output terminals of the rectifier are the positive and negative sides of the direct current line and are connected to a conventional voltage regulator 32 by conductors 33 and 34, respectively. The negative side of the line is grounded as at 23'.

The battery terminal of voltage regulator 32 is connected to the positive side of a twelve volt storage battery 35 by a conductor 36 through an ammeter 31 which is shunted across the line. The ignition terminal of voltage regulator 32 is connected by a conductor 38 with the closing contact 39 of a relay 40. The movable contact 4| of relay 46 is connected with conductor 36 by a, conductor 42. The armature coil 43 of relay is grounded at one end as at 44 and is connected at its other end by a conductor 45 to one side of an ignition switch 46. The other side of switch 46 is connected to the positive side of a conventional six volt storage battery 41 by a conductor 48 through an ammeter 49. The negative side of battery 41 is grounded as at 50 and the negative side of battery 35 is grounded as at 5!. The lighting circuit for the vehicle is connected with battery conductor 48 as at 52. The ignition circuit for the vehicle engine is connected to battery 4'! beyond switch 46 as at 53 with conductor 45.

The field of alternator 25 is arranged to be excited by battery 35 when ignition switch 46 is turned on and is accordingly connected at one end to a load relay circuit (not shown) in voltage regulator 32 by a conductor 55. The other end of the field coil of alternator 25 is connected to ground 23 by a conductor 56.

Compressor motor H is connected to battery 35 through a relay 66. The movable contact 6! of relay is connected by a conductor 62 with conductor 36 and the closing contact 63 of relay 66 is connected with motor II by a conductor 64. The armature coil 65 of relay 66 is grounded at one end as at 66 and connected at the other end by conductor 61 with one terminal 68 of a three pole, double throw switch .at 92: and H3.

switch 14 is connected by conductors 15 and 16 in series with center terminals 11 and 18 of switch 69. The other center terminal 19 of switch 69 is connected with fan motor 22 by a conductor 80. Motors 22 and II are grounded as at 8| and 82 respectively.

For operating. the refrigerating apparatusfrom a standard 110 volt A. C. outlet there is provided a pair of conductors 85 and 86 which may be provided at one end with a convention plug (not shown). 85 and 86 are connected to the high side of a step down transformer 81, the low side of which is connected to the input side. of a rectifier 38.. The negative line of rectifier 88 is grounded as at 89 while the positive line of rectifier 83 is connected by a conductor 93 with a terminal 91. of switch 69 on the opposite side of terminals 58, 10, and H. The other two terminals of switch 69 on the same side as terminal SI are designated Terminal 92 is connected by a conductor 3.45 with one end. of the armature coil 95 of a relay 96.. The other end of coil 95 is grounded as at. 91'. A conductor 98; connects the moo-able. contact 99 of relay 65 with conductor 911; the closing contact II9 of relay 95 being connected-with conductor- 6.1: by conductor I03. Terminal 9.2: of switch. 69 is, alsov connected to one endof the. armature coil; IflI- of a. relay I02 by conductor I53. The; other end of coil IllzI is: grounded", as at I634... Relay I02 has its movable contact I 05 connected with battery conductor 62 by a. conductor I186. The closing contact I01 or relay [=02 connected: with, conductor 90.. A relay tIIIs has its. armature coil- III: connected across: conductors 85; and 86 by means of a pair of conductors H2 and I13. The movable con tact. I14 of relay II 0.: is connected withv conductor 62 and battery 35 bya conductor 5.. Relay Hill has. its closing contact II-t connected with terminal 93: of switch 63 by a conductor I I6. A fan H1 is connected across conductors H2 and H3 and is arranged to cool, rectifier 8.8 when conductors 85 and'86 are connected into asource ofi no: volt alternating current.

Alternator 25 is arranged to provide current for charging not only battery 35 but. also battery 41. For purpose there is provided a conductor [2 0' is connected at one endi'to the positive conductor 33 leading from rectifier 28 and at its other end to a resistancebank I12I. Resistance bank; I2I. comprises two sets of resistors t2;2 and t23 connected in parallel with conductor I20, the total resistance of resistors I22 being much less than the total. resistance of resistors I23. Both sets: of; resistors are; connected in parallel to bat.- tery 4-1. by-a conductor I24 and a relay I125. Conductor I24 is connected between the closing contact I26 of relay I and battery conductor 48. The movablecontact I21 of relay I 25 isconnected by a conductor I23 with resistors I23. Relay I25 has its armature coil I29 connected at one end by a conductor I36- with conductor 45 and is grounded at the other end as at I31. Resistors I122 are also connected with conductor I28 by a conductor I32, a relay I33. and a conductor I34. Conductor I32 connects. with the movable contact I of relay [33- and conductor I34 connects with the closing contact I36 of relay I 33. Relay I33 isv arranged to be controlled, by a. voltage sensitive relay [36. having a movable contact I39 connected by a conductor I146 with one end of the armature coil I42 of relay I33 and a closing contact I43 connected by a conductor I44 with conductor I28. The sensitive armature coil I45 of relay 1.38 is connected at one end with conductor I44. Coils At their other ends conductors.

I42 and I45 are grounded as at I46 and I41, respectively. The movable contact I 39 of relay I38 is biased to the closed position, the coil I45 of the relay being sensitive to the E. M. F. across battery 41 such that when the voltage across the battery drops below a predetermined value, the current-through coil I45-isinsuflicient to hold the relay closed, and the movable contact I39 is pulled to close with contact I43.

When it is desired to operate the refrigerating apparatusfrom. battery 35 and alternator 25, the handle of switch 69 is closed with the contacts on the battery side of the switch and ignition switch, 45;closed1to enable starting of the engine.

' closing of switch 46 closes a circuit from battery 4-1; through conductors 48 and 45 and the armature coil. 1:3. of relay 4!]. When relay 40 pulls in, current flows from either battery 35 or voltage regulator 32 through conductors 33 and 42, contacts 4I and 39, and conductors 12 and 13 to terminal H on a, switch 69... From terminal 1] the current flows through the switch to terminal 19 and then through conductor to the, fan motor 22'. Fan motor 22 will therefore operate continually when ignition switch 46 is turned to the on position and switch 69 closed with the battery side of. the circuit- Thermostatic switch 14 is; locatedin. the refrigerating compartment of the vehicle (not shown) and; if the temperature of the compartment is above the setting of switch 14., current through conductor which is: connectedwith terminal 150: of switch 33'. also flows through conductor I6, switchv 14, conductor 15, terminals 111 and; 63; and conductor 61130 the armature coil 65. of relay 33. Relay 60 thereby pulls in and closes a. circuit between battery 35 or voltage regulator 32' and: compressor motor 'I I through conductor 62', contacts 61? andfi3 of relay 66,. and conductor 64. Compressor motor II is thereby set. in operation. the temperature of the refrigerating compartmentfalls' to the setting of switch 14, switch 54 opens, thereby opening the circuit through coil 65 of relay 30 and the relay: tall-s out to open the circuit to the compressor motor. It wiil be appreciated, of course, that battery 35- suppl'ies the'extra current required; when the current through voltageregulater 32 insufficient to meet the demands of compressor motor I I, such as whenmotor II draws an excessive starting current. 'When the voltage across battery 35 fallsbelow twelve volts, it is charged through conductor 36 by thecurrent flowing from voltage regulator 32.

In the arrangement shown, alternator 25 is preferably designed to generate about amperes at fourteen volts. An alternator of this capacity is sufiicient in the arrangement shown to charge both battery 35 and battery 41. When the voltage across battery 41 is at or near its seven volt rating, movable contact I39 of relay I33 is held by coil I45 in the open position. Coil M5 is designed to. hold contact ['39 in the open position as long as the voltage across battery 41 exceeds a predetermined value, such as, for

instance, six and one-half volts. Therefore, during normal operation, when the E. M. F. across battery 41 is more than seven volts, the circuit through resistors I22 is open and the only current flowing from rectifier 28- to battery 41 and the ignition and lighting circuits of the vehicle is that which flows through resistors I23. When ignition switch 46 is closed a circuit from battery 41 to relay I25 is closed throughconductors 43 and f3'6 and coil I 24. This causes relay I25 to pull in so that a circuit is closed through con- 5 "ductor I20,r e si'stors I23, conductor n, contacts I2Iand I26, and conductors I24, 48 and 45 to the ignition and lighting circuits" of the vehicle.

Resistors I 23 aredesigned such that current flow When the engine of the vehicle is started or when an excessive load isplaced on the lighting circuit, it will be appreciated that the voltage across battery 41 will be drop below a normal value. When this occurs, contact I39 of relay I38 will fall out and close with contact I43. The current in the conductor I39 will/then flow through conductor I44, contacts I43 and I39, conductor I40, and'through coil I42 of relay. I33. The closingof relay I 38 thereby pulls in relay I33 which closes acircuit through conductor I20, resistors 122; conductor I32, contacts I35 and I36, conductors I34and I28, through relay I25 and conductor I24 to battery 41. Resistors I22 are designed such that the current flowing therethrough is greatly in excess of the current flowing through resistors I23. That is, while the current through resistors I23 is about 4 amperes, the current flowing through resistors I22 is in the neighborhood of 30 amperes. This large current serves to charge battery 41 back to its normal rating of seven volts. When the voltage across battery 41 approaches seven volts, movable contact I39 of relay I38 is pulled to the open position thereby opening the circuit through resistors I22 and permiting the trickle charge to flow through resistors I23.

When the vehicle engine is stopped and it is desired to continue the operation of the refrigerating apparatus, such as when the vehicle is parked overnight, the handle of switch 69 is shifted to close with the contacts on the external power source side of the switch. With switch 69 in this position, conductors 85 and 86 may be connected with a 110 volt alternating current outlet to operate the refrigerating apparatus. When conductors 85 and 86 are connected with a source of alternating current, it will be noted that a circuit is closed through coil III of relay III) and fan motor I I! by conductors I I2 and I I3. Relay H is thereby pulled in to close a circuit from battery 35 through conductor II5, contacts H4 and H8, conductor II6, terminals 93 and I9, and conductor 80 to fan motor 22. Fan motor 22 is therefore in continual operation when conductors 85 and 86 are plugged into a source of alternating current. When switch I4 is closed, that is, when the temperature of the refrigerating compartment is above the setting of the switch, current also fiows through transformer 81, rectifier 80, conductors 90, terminals 9I and I8, conductor I6, through switch I4, conductor I5, terminals I1 and 92, and from terminal 92 through conductor I03 to coil IOI of relay I02. The current flowing through switch I4 also flows from terminal 92 through conductor 94 and coil 95 of relay 96. The movable contacts 99 and I of relays 96 and I02 respectively are thereby pulled to the closed position. The closing of relay 96 closes a circuit from the rectifier through conductors 90 and 98, contacts 99 and I I9, conductors I00 and 61, and coil 65 of relay 60. With relays 60 and I02 both pulled in, a circuit is closed from rectifier 88 through conductor 90, contacts I01 and I05, conductor I06, contacts SI and 63, and

conductor 64 to compressor motor I I. When the temperature within the refrigerating compartment falls to the setting of switch I4, relays 96,

I02, and 60 fall out and thereby open the circuit to the compressor motor and battery 35.

I claim:

1. A refrigerating apparatus for a motor vehicle of the type having a refrigerating compartment comprising an alternator arranged to be driven by the engine of the vehicle, a rectifier connected with the output side of said alternator, a refrigerating apparatus on said vehicle,'a direct current motor for operating said refrigerating apparatus, said motor being connected with said rectifier for operation by said alternat'onp, first battery connected with said rectifier and said refrigerating apparatus motor, said vehicle including an ignition and a lighting circuit connected with said rectifier, and a second battery connected with said rectifier and said ignition and lighting circuits, said batteries each being arranged to be charged by the current supplied by said alternator.

2. The combination set forth in claim 1 including electrically actuated means connected with said second battery and operative to connect and disconnect said first battery with said refrigerating apparatus motor and switch means for controlling the supply of current to said electrically actuated means, whereby said first battery is prevented from supplying current to said motor unless said switch means is actuated to permit current to flow from said second battery to said electrically actuated means.

3. The combination set forth in claim 1 including a thermostatic switch between said motor and said first battery and alternator for controlling the flow of current from said first battery and alternator to said motor, said thermostatic switch being responsive to the temperature of said refrigerating compartment for opening and closing the circuit including said first battery, said alternator and said motor.

4. A refrigerating apparatus for a vehicle of the type having a refrigerating compartment and a lighting and ignition circuit designed to be operated on a low voltage comprising a refrigerating apparatus in said refrigerating compartment, a direct current motor for operating said refrigerating apparatus, said motor being de-' signed for operation at substantially higher volt age than the voltage requirements of said ignition and lighting circuit, an alternator adapted to generate current at the voltage requirements of said motor, a rectifier connected with the output side of said alternator, means connecting said motor with the direct current side of said rectifier, a battery having a normal voltage corresponding to the voltage requirements of said motor, said battery being arranged to supply current to said motor and to be charged by said alternator, a second battery having a normal voltage corresponding to the voltage requirements of said lighting and ignition circuit and connected with said lighting and ignition circuit for supplying current thereto, and means connecting said second battery with said rectifier for charging said second battery from said alternator, said last mentioned means being arranged to reduce the voltage supplied to said second battery from said alternator and to control the current supplied to said second battery in accordance with the load on said lighting and ignition circuit.

5. The combination set forth in claim 4 wheresaid last mentioned rneans: comprises; means formmg anormally closedcircuit of high. resistancebetwee'n saidsecondbattery 'and said alternator; meansrforming. a normally opened circuit of low resistance between said alternator and said second battery, the resistance of said: circuit of. high resistance being such that thecurrent flowing through said circuit from said alternator is sufficient-to meet only thetnormal demands of said; lightingand ignition circuit, theresistance of said low resistance circuit beingsuch that the current flowing therethrough, from saidalternator .is; relatively large as compared with the current flowingthrough said highresistance circuit, and means responsive to the voltage across said second battery for closing, said circuit of low resistance when the voltage across said second battery falls belowa predetermined value.

6; Thecombination set forth in claim-5 wherein: said means for closing said low resistancecircuitcomprises a; voltage sensitive relay in said low resistance circuithaving an armature coil connected with said second battery.

"7. The combination setforth in claim 5 wherein said high and low resistance circuits are connected in parallel between said battery and said alternator, said: means for closing saidcircuit of low" resistance comprising a: voltage sensitive relay in said: low' resistance-circuit: having an armature 0011- connected to said second battery, said relay having a pair of normally open contacts providing a break in said low resistance circuit, said contacts being-arranged to close when the voltageacrosssaid second battery falls below said a predetermined value.

HENRY O; KIRKPATRICK.

REFERENCES CITED The following references" are of. record in the file of this patent:

UNITED- STATES PATENTS 

